btrfs: do not return errors from btrfs_submit_dio_bio

Always consume the bio and call the end_io handler on error instead of
returning an error and letting the caller handle it.  This matches what
the block layer submission and the other btrfs bio submission handlers do
and avoids any confusion on who needs to handle errors.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/inode.c

@@ -8014,8 +8014,8 @@ static void btrfs_end_dio_bio(struct bio *bio)
 	btrfs_dio_private_put(dip);
 }
 
-static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
-		struct inode *inode, u64 file_offset, int async_submit)
+static void btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
+				 u64 file_offset, int async_submit)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_dio_private *dip = bio->bi_private;
@@ -8029,22 +8029,24 @@ static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
 		if (async_submit && !atomic_read(&BTRFS_I(inode)->sync_writers) &&
 		    btrfs_wq_submit_bio(inode, bio, 0, file_offset,
 					btrfs_submit_bio_start_direct_io))
-			return BLK_STS_OK;
+			return;
 
 		/*
 		 * If we aren't doing async submit, calculate the csum of the
 		 * bio now.
 		 */
 		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, file_offset, false);
-		if (ret)
-			return ret;
+		if (ret) {
+			bio->bi_status = ret;
+			bio_endio(bio);
+			return;
+		}
 	} else {
 		btrfs_bio(bio)->csum = btrfs_csum_ptr(fs_info, dip->csums,
 						      file_offset - dip->file_offset);
 	}
 map:
 	btrfs_submit_bio(fs_info, bio, 0);
-	return BLK_STS_OK;
 }
 
 static void btrfs_submit_direct(const struct iomap_iter *iter,
@@ -8157,14 +8159,7 @@ static void btrfs_submit_direct(const struct iomap_iter *iter,
 				async_submit = 1;
 		}
 
-		status = btrfs_submit_dio_bio(bio, inode, file_offset,
-						async_submit);
-		if (status) {
-			bio_put(bio);
-			if (submit_len > 0)
-				refcount_dec(&dip->refs);
-			goto out_err_em;
-		}
+		btrfs_submit_dio_bio(bio, inode, file_offset, async_submit);
 
 		dio_data->submitted += clone_len;
 		clone_offset += clone_len;